package org.atlantis.uzw.utils;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.security.Key;
import java.security.spec.KeySpec;

import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang3.StringEscapeUtils;

/**
 * 编码工具类
 * 
 * @author <a href="mailto:seenoevil.cn@gmail.com">李曦</a><br/>
 *         Created at: 2013-7-26 下午2:49:17
 */
public class Encodes {

	private static final String CHARSET_NAME = "UTF-8";
	private static final char[] BASE62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".toCharArray();

	// for des
	private static final Key DES_KEY;
	private static final String DES = "DES";

	static {
		try {
			KeySpec keySpec = new DESKeySpec("L0)I>=J8AQZsQa>R!w4^3yY4WDo;cc+_".getBytes(CHARSET_NAME));
			DES_KEY = SecretKeyFactory.getInstance(DES).generateSecret(keySpec);
		} catch (Exception e) {
			throw Exceptions.unchecked(e);
		}
	}

	/**
	 * Hex编码
	 */
	public static String encodeHex(byte[] input) {
		return Hex.encodeHexString(input);
	}

	/**
	 * Hex解码
	 */
	public static byte[] decodeHex(String input) {
		try {
			return Hex.decodeHex(input.toCharArray());
		} catch (DecoderException e) {
			throw Exceptions.unchecked(e);
		}
	}

	/**
	 * Base64编码
	 */
	public static String encodeBase64(byte[] input) {
		return Base64.encodeBase64String(input);
	}

	/**
	 * Base64编码, URL安全(将Base64中的URL非法字符'+'和'/'转为'-'和'_', 见RFC3548)
	 */
	public static String encodeUrlSafeBase64(byte[] input) {
		return Base64.encodeBase64URLSafeString(input);
	}

	/**
	 * Base64解码
	 */
	public static byte[] decodeBase64(String input) {
		return Base64.decodeBase64(input);
	}

	/**
	 * Base62编码
	 */
	public static String encodeBase62(byte[] input) {
		char[] chars = new char[input.length];
		for (int i = 0; i < input.length; i++) {
			chars[i] = BASE62[((input[i] & 0xFF) % BASE62.length)];
		}
		return new String(chars);
	}

	/**
	 * Html 转码
	 */
	public static String escapeHtml(String html) {
		return StringEscapeUtils.escapeHtml4(html);
	}

	/**
	 * Html 解码
	 */
	public static String unescapeHtml(String htmlEscaped) {
		return StringEscapeUtils.unescapeHtml4(htmlEscaped);
	}

	/**
	 * Xml 转码
	 */
	public static String escapeXml(String xml) {
		return StringEscapeUtils.escapeXml(xml);
	}

	/**
	 * Xml 解码
	 */
	public static String unescapeXml(String xmlEscaped) {
		return StringEscapeUtils.unescapeXml(xmlEscaped);
	}

	/**
	 * URL 编码, Encode默认为UTF-8
	 */
	public static String urlEncode(String part) {
		try {
			return URLEncoder.encode(part, CHARSET_NAME);
		} catch (UnsupportedEncodingException e) {
			throw Exceptions.unchecked(e);
		}
	}

	/**
	 * URL 解码, Encode默认为UTF-8
	 */
	public static String urlDecode(String part) {

		try {
			return URLDecoder.decode(part, CHARSET_NAME);
		} catch (UnsupportedEncodingException e) {
			throw Exceptions.unchecked(e);
		}
	}

	/**
	 * DES编码
	 */
	public static String encodeDES(String part) {
		try {
			Cipher cipher = Cipher.getInstance(DES);
			cipher.init(Cipher.ENCRYPT_MODE, DES_KEY);
			return URLEncoder.encode(Base64.encodeBase64String(cipher.doFinal(part.getBytes(CHARSET_NAME))), "UTF-8");
		} catch (Exception e) {
			throw Exceptions.unchecked(e);
		}
	}

	/**
	 * DES解码
	 */
	public static String decodeDES(String part) {
		try {
			Cipher cipher = Cipher.getInstance(DES);
			cipher.init(Cipher.DECRYPT_MODE, DES_KEY);
			return new String(cipher.doFinal(Base64.decodeBase64(URLDecoder.decode(part, "UTF-8"))), CHARSET_NAME);
		} catch (Exception e) {
			throw Exceptions.unchecked(e);
		}
	}
}
